It is known that pilots and flight attendants are exposed to a higher level of radiation, starting from that one which comes out of ground devices and finishing with sun radiation. I've seen several discussions on this subject here, but still I can't settle down with exact figures. Let's put it this way:

- which is considered to be safe amount of radiation for a ususal person (not working in somewhat high radiation area)?
- what is the average amount a pilot gets from one flight?

That's really no different than what John Doe walking down the street gets. Pilots, if anything might get a bit more radiation from the WX radars on the planes. But everybody is subject to ILS, VOR, TACAN, MLS, radar, etc radiation whether a pilot or not.

Quoting FLY2HMO (Reply 1):That's really no different than what John Doe walking down the street gets. Pilots, if anything might get a bit more radiation from the WX radars on the planes. But everybody is subject to ILS, VOR, TACAN, MLS, radar, etc radiation whether a pilot or not.

That's a different type of radiation, though. RF (Radio Frequency) radiation is non-ionizing (meaning, that when it penetrates your body, it doesn't create ions that do nasty things like break up DNA molecules while your cells are reproducing...)

I believe that what user Longitude is requesting is concrete data on ionizing radiation (like, for example, excess UV radiation that pours into the cockpit at FL410 on a sunny day, or the cosmic background radiation that you get at altitude, which John Doe on the ground doesn't get because the denser atmosphere ath the surface blocks it...).

Flight crews and frequent flyers are known to be exposed to more ionizing radiation than those of us who spend the majority of our days at ground level

Quoting KELPkid (Reply 2):RF (Radio Frequency) radiation is non-ionizing (meaning, that when it penetrates your body, it doesn't create ions that do nasty things like break up DNA molecules while your cells are reproducing...)

True, but IIRC if the signal is strong enough it can still do that, of course, your average NAVAID only puts out a couple of watts.

Yes, I am worried about, let's say, harmfull radiation which pilots are exposed to, no matter whether it comes from the devices or the sun.
Fly2HMO, of course, all the people who are aboard the plane are affected by ILS, VOR, etc. But pilots are much more frequent visitors aboard, rather than a certain person , so what I am trying to find out - is how much more they get in comparison to an average office employee. And also what they can do to prevent themselves from getting this additional radiation doze.

The higher and longer you stay up the more gamma radiation you will receive. It's not a huge amount, 5-8 mSv/year over the normal 2-3 mSv/year you would receive from the back ground radiation here in Canada, other countries vary because of elevation and soil conditions. You don't really have to worry about doses like that, even if you worked as a pilot or miner for 50 years and got 20mSv/year your chances of getting cancer are only increased by 3-4 percent. It's when you get into acute doses that a person will feel the effects, we're talking huge doses, think the workers who went into Chernobyl after the initial accident and were exposed to how many Grays of radiation, they died within days to weeks and it wasn't pretty.

The body does in fact clean itself up from mild radiation doses, so as Tesko says the extra risk of cancer is quite small, perhaps even negligible. Factors like genetics will have a much bigger impact on any given individual.

"There are no stupid questions, but there are a lot of inquisitive idiots."

Quoting Longitude (Reply 4):. But pilots are much more frequent visitors aboard, rather than a certain person , so what I am trying to find out - is how much more they get in comparison to an average office employee.

Heh, I'm a network administrator, and for about 16 years of my life, I spent lots of time in front of CRT displays (multiple ones, many times) that put off low doses of X-rays...(maybe more when your bored co-workers do things like attach magnets to the screen to liven things up!)

Wonder how much excess ionizing radiation I got form that

I am so glad that LCD displays are the new standard in information technology...

Standards vary somewhat from country to country, but for most members of the public, the standard is around 1mSv/yr for non-natural/non-deliberate (ie. medical) radiation exposure. Note that the average background exposure is about 2.4mSv/yr (in the US it's closer to 3mSv/yr, because we have a lot of radon producing rock).

Occupational exposure limits are higher, typically in the 20-50mSV/yr range, and in some cases those are a couple of separate categories (with higher limits for workers directly working with radiation sources). In the US, the occupational limits for minors is 5mV/yr, for pregnant women, 5mSv over the course of the pregnancy.

Anyway, exposure for flights varies by altitude and latitude, and things like the sunspot cycle, but is generally 1-10 uSv/hr. Summarizing from an Australian report:

True, but IIRC if the signal is strong enough it can still do that, of course, your average NAVAID only puts out a couple of watts.

So, this happens rarely as well? Or should it still be taken into account?

Quoting KELPkid (Reply 7):Heh, I'm a network administrator, and for about 16 years of my life, I spent lots of time in front of CRT displays (multiple ones, many times) that put off low doses of X-rays...(maybe more when your bored co-workers do things like attach magnets to the screen to liven things up!)

The Earth's magnetic field captures radiation from space and diverts it towards the poles.

Think about how your compass works: somewhat imaginary "lines of magnetic flux" emanate out of the Earth at the north pole and point towards the south pole. The magnetic needle in the compass aligns itself with these lines so it always points towards the north pole. The poles of the magnet in the compass are magnetically charged, and opposite charges attract, so the charged poles of the Earth attract the charged poles of the magnet in the compass, which is how it aligns itself properly.

Likewise, radiation particles are (electrically) charged, and so the magnetic poles of the Earth attract them, directing the energy in the radiation towards the ground near the sparsely populated magnetic poles.

If you can imagine the lines of flux coming into/going out of the Earth at the poles, you can visualize that near the poles, the angle of the lines with respect to the ground is nearly vertical, whereas near the equator, the lines are nearly parallel to the ground. Near the equator, then, the lines are at a great altitude above the surface, while at the poles, they actually contact the surface. So, radiation is picked up and channeled away from the atmosphere at a very high altitude near the equator, but towards the poles, the radiation concentrates and is present in the atmosphere all the way to the ground. This is why the exposure is higher near the poles at any altitude (and also why we see the aurora near the poles).

If it is known, that for a person a safe dose of radiation is, for example 1, then any person, who gets 3 due to the fact they are working in higher radiation area, still gets 3 times the safe amount! What is the meaning of "occupational limits" then? Does it basically come out this way "ok, somebody has to work in high radiation level areas. These people will definitely get higher level of radiation than that one which is considered safe limit. So let us establish a new higher norm for them, in between the safe one and the one which will do much harm to their health"?

I also found another interesting link
According to the investigation of cockpits radiation level, conducted in 1988-1993 by specialists of State Scientific and Research CIvil Aviation Institute (?), american biologists, radiation doses the crew gets on different altitudes are as follows:
9000 meters(!) - 226,8 micro-roentgen/hr
10000 meters - 307 micro-roentgen/hr
11000 meters - 351 micro-roentgen/hr
12000 meters - 404 micro-roentgen/hr
Taking into account that the amount of radiation at the earth level up to 1000 meters is 9,99 micro-roentgen/hr, we can conclude that the normal doses are exceeded by:
9000 meters - 31 times
11000 meters - 35 times
12000 meters - 41 times.

Quoting Longitude (Reply 12):If it is known, that for a person a safe dose of radiation is, for example 1, then any person, who gets 3 due to the fact they are working in higher radiation area, still gets 3 times the safe amount! What is the meaning of "occupational limits" then? Does it basically come out this way "ok, somebody has to work in high radiation level areas. These people will definitely get higher level of radiation than that one which is considered safe limit. So let us establish a new higher norm for them, in between the safe one and the one which will do much harm to their health"?

No. Your "1" is simply the radiation that a person receives by just being on Earth. 3 is not unsafe, just higher than what would be received if the person did not have that job.

"There are no stupid questions, but there are a lot of inquisitive idiots."

Quoting Longitude (Reply 12):If it is known, that for a person a safe dose of radiation is, for example 1, then any person, who gets 3 due to the fact they are working in higher radiation area, still gets 3 times the safe amount! What is the meaning of "occupational limits" then? Does it basically come out this way "ok, somebody has to work in high radiation level areas. These people will definitely get higher level of radiation than that one which is considered safe limit. So let us establish a new higher norm for them, in between the safe one and the one which will do much harm to their health"?

I hesitate to comment on what a "safe" level of radiation exposure is. There are many people (myself not included) who feel that any amount is dangerous, although that clearly presents a practical issue given the background exposure.

But, the occupational standards are usually considered safe, it's just that the standards for exposure to the public (who did not consent to the exposure) are much lower.

Some general comments:

- The average radiation worker in the US gets an annual occupational exposure of about 1.2mSv, although obviously individuals can be much higher or lower.

- An acute (accumulated over a brief time) dose of 100mSv is considered to increase your lifetime cancer risk by .8%

- The US EPA allows workers to volunteer for emergency (non-life saving) work with acute exposures up to 250mSv. For life-saving emergencies, you can volunteer for a 750mSv dose.

- Acute exposures of 500mSV and up start to cause radiation sickness. Full (at least short term) recovery is expected for essentially all people at 50mSv, while 50% will die from a 5000mSv exposure, even with supportive medical care.

Quoting Longitude (Reply 12):I also found another interesting link
According to the investigation of cockpits radiation level, conducted in 1988-1993 by specialists of State Scientific and Research CIvil Aviation Institute (?), american biologists, radiation doses the crew gets on different altitudes are as follows:
9000 meters(!) - 226,8 micro-roentgen/hr
10000 meters - 307 micro-roentgen/hr
11000 meters - 351 micro-roentgen/hr
12000 meters - 404 micro-roentgen/hr
Taking into account that the amount of radiation at the earth level up to 1000 meters is 9,99 micro-roentgen/hr, we can conclude that the normal doses are exceeded by:
9000 meters - 31 times
11000 meters - 35 times
12000 meters - 41 times.

Those numbers seem rather high, unless you're just looking at the cosmic radiation exposure (and ignoring the other radiation sources at ground level). And let's please not measure radiation exposure in Röntgens - at best that's appropriate for raw ionizing radiation measurements, and does not take into account biological impact or differences in radiation types. Use Sieverts. Or rems if you want to be old fashioned...

I won't get too much into this but we wear radiation badges like any cargo guy and they record every exposure every flight and a nuc med professor saw my mo. reading and said I get more radition when I sit out by the pool on my layover. The avg person gets about 75% of their radition from the ground, air and med treatments as well as food.

Quoting Rwessel (Reply 14):- Acute exposures of 500mSV and up start to cause radiation sickness. Full (at least short term) recovery is expected for essentially all people at 50mSv, while 50% will die from a 5000mSv exposure, even with supportive medical care.

Should have been:

- Acute exposures of 500mSV and up start to cause radiation sickness. Full (at least short term) recovery is expected for essentially all people at **500mSv**, while 50% will die from a 5000mSv exposure, even with supportive medical care.

Quoting CosmicCruiser (Reply 15):I've got bad news for you...your constantly bombarded from space as well as the ground in the form of Radon which varies by location but is 24/7/365

Quoting Rwessel (Reply 14):And let's please not measure radiation exposure in Röntgens - at best that's appropriate for raw ionizing radiation measurements, and does not take into account biological impact or differences in radiation types. Use Sieverts. Or rems if you want to be old fashioned...

The Supersonic Transport (SST) program, proposed in 1961, first raised concern for the exposure of pregnant occupants by solar energetic particles (SEP), and neutrons were suspected to have a main role in particle propagation deep into the atmosphere. An eight-year flight program confirmed the role of SEP as a significant hazard and of the neutrons as contributing over half of the galactic cosmic ray (GCR) exposures, with the largest contribution from neutrons above 10 MeV. The FAA Advisory Committee on the Radiobiological Aspects of the SST provided operational requirements. The more recent (1990) lowering of recommended exposure limits by the International Commission on Radiological Protection with the classification of aircrew as "radiation workers" renewed interest in GCR background exposures at commercial flight altitudes and stimulated epidemiological studies in Europe, Japan, Canada and the USA. The proposed development of a High Speed Civil Transport (HSCT) required validation of the role of high-energy neutrons, and this resulted in ER-2 flights at solar minimum (June 1997) and studies on effects of aircraft materials on interior exposures. Recent evaluation of health outcomes of DOE nuclear workers resulted in legislation for health compensation in year 2000 and recent European aircrew epidemiological studies of health outcomes bring renewed interest in aircraft radiation exposures. As improved radiation models become available, it is imperative that a corresponding epidemiological program of US aircrew be implemented.

Quoting Bri2k1 (Reply 11):Likewise, radiation particles are (electrically) charged, and so the magnetic poles of the Earth attract them, directing the energy in the radiation towards the ground near the sparsely populated magnetic poles.

Charged particles (alpha or beta radiation) would be diverted by a magnetic field. Gamma (or any other form of electromagnetic radiation) will not be diverted by a magnetic field.
Cosmic radiation is mostly energetic protons and would be diverted. UV, x-rays, gamma rays, etc. would not be diverted by magnetic fields but could be "intercepted" by dust, ozone, etc. I'm not sure what the breakdown of radiation is in terms of charged particles vs. electronmagnetic.

I don't have any technical expertise in the area of radiation, however, I did stumble upon this calculator. To be honest, this whole area isn't much of a concern for pilots and this calculator would be considered a fun oddity by most.